I don't know that I have ever read a book that was so emotionally draining I had to put it down. I have read books that have made me cry, see my post about Little Women. There are books that cause me to be upset or angry, but I can't think of a book that is overly emotional. Here are books that took me off guard and caused some tears:
The end of this book signaled a shift in the tone of series. We found out that Voldermort truly was evil and that he was willing to do anything to return to power. A truly innocent character pays the ultimate price for being a good person, and I cried with Harry.
I recently read this and cried when Claire writes her letter to Bree, and when Jamie looks at Bree's pictures.
Rue+flowers+signing+plus the signal= a sobbing Juli Ann.
Once again Rowling raises the stakes, and Harry loses someone else he loves. The lose of a mentor and surrogate father in an intensely tragic situation was heart wrenching.
This book gets you with Hedwig and keeps punching till the end.